Power augmentation system with dynamics damping

ABSTRACT

A power augmentation system for a gas turbine engine which may include a transition piece of a combustor and a steam manifold positioned about the transition piece. The transition piece may include a number of transition piece passageways therethrough and the steam manifold may include a number of manifold passageways therethrough. The manifold passageways align with the transition piece passageways.

CROSS-REFERENCE TO RELATED APPLICATION

This is a national stage application under 35 U.S.C. §371(c) prior-filedco-pending PCT patent application serial number PCT/RU2011/00226, filedon Mar. 31, 2011, the entire contents of which are incorporated hereinby reference.

TECHNICAL FIELD

The present application relates generally to gas turbine engines andmore particularly relates to a steam manifold positioned about atransition piece of a combustor so as to provide power augmentation anddynamics damping.

BACKGROUND OF THE INVENTION

Using a lean fuel air mixture is a known method of decreasing NO_(x)emissions and currently is in use in multiple designs of gas turbinecombustion systems. The lean fuel air mixture includes an amount of fuelpremixed with a large amount of excess air. Although such a lean mixturereduces the amount of NO_(x) emissions, high frequency combustioninstabilities may result. Such instabilities may be referred to ascombustion dynamics. These instabilities may be caused by burning ratefluctuations and may create damaging pressure oscillations that mayimpact on gas turbine durability. As a result of these instabilities,damping or resonating devices may be used with the combustor.

Providing additional mass flow into a gas turbine is a known method ofenhancing overall gas turbine engine power output and efficiency. Steaminjection is commonly used for this purpose. For instance, about a fivepercent (5%) steam addition to a gas turbine combined cycle system mayresult in about a ten percent (10%) output increase. Issues may arise,however, because the steam may impact on flame stability and freeze COoxidation in the combustor. As such, the use of steam injection maylimit overall emissions and turndown capabilities of gas turbines.

There is therefore a desire for improved combustion dynamics damping aswell as power augmentation systems and methods. Preferably, such systemsand methods may increase overall system performance and efficiency whilereducing combustion dynamics.

SUMMARY OF THE INVENTION

The present application thus provides a power augmentation system for agas turbine engine. The power augmentation system may include atransition piece of a combustor and a steam manifold positioned aboutthe transition piece. The transition piece may include a number oftransition piece passageways therethrough and the steam manifold mayinclude a number of manifold passageways therethrough. The manifoldpassageways may align with the transition piece passageways.

The present application further provides a power augmentation system fora gas turbine engine. The power augmentation system may include atransition piece of a combustor and a steam manifold positioned aboutthe transition piece. The transition piece may include a number ofapertures extending therethrough and the steam manifold may include anumber of tubes extending therethrough such that the apertures alignwith the tubes. The tubes may include a predetermined size based uponthe frequency of the combustor.

The present application further provides a power augmentation system fora gas turbine engine. The power augmentation system may include acombustor and a steam manifold positioned about the combustor. Thecombustor may include a number of apertures extending therethrough andthe steam manifold may include a number of tubes extending therethrough.The tubes may include a predetermined size based upon the frequency ofthe combustor.

These and other features and improvements of the present applicationwill become apparent to one of ordinary skill in the art upon review ofthe following detailed description when taken in conjunction with theseveral drawings and the appended claims.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic view of a gas turbine engine.

FIG. 2 is a perspective view of a steam manifold system as is describedherein.

FIG. 3 is a side cross-sectional view of the steam manifold system ofFIG. 2.

FIG. 4 is a further side cross-sectional view of the steam manifoldsystem of FIG. 2.

DETAILED DESCRIPTION

Referring now to the drawings, in which like numbers refer to likeelements throughout the several views, FIG. 1 shows a schematic view ofa gas turbine engine 10. As is known, the gas turbine engine 10 mayinclude a compressor 20 to compress an incoming flow of air. Thecompressor 20 delivers the compressed flow of air to a combustor 30. Thecombustor 30 mixes the compressed flow of air with the compressed flowof fuel and ignites the mixture. (Although only a single combustor 30 isshown, the gas turbine engine 10 may include any number of combustors30.) The hot combustion gases are in turn delivered to a turbine 40. Thehot combustion gases drive the turbine 40 so as to produce mechanicalwork. The mechanical work produced in the turbine 40 drives thecompressor 20 and an external load 50 such as an electrical generatorand the like. The gas turbine engine 10 may use natural gas, varioustypes of syngas, and other types of fuel. The gas turbine engine 10 mayhave many other configurations and may use other types of components.Multiple gas turbine engines 10, other types of turbines, and othertypes of power generation equipment may be used herein together.

FIGS. 2-4 show a power augmentation system with dynamics damping or asteam manifold system 100 as is described herein. The steam manifoldsystem 100 may be positioned at an end 110 of a transition piece 120 ofthe combustor 30. The transition piece 120 directs a stream of hotexhaust gases 125 from the combustor 30 to the turbine 40 as isdescribed above. The transition piece 120 may have a number of apertures130 positioned about the end 110 thereof. Any number of the apertures130 may be used. Some of the apertures 130 may be positioned at an anglewith respect to the direction of the stream of hot exhaust gases 125through the combustor 30. The angle may be about 30 to about 60 degrees,although any desired angle may be used herein. The apertures 130 mayhave any desired size or shape as is described in more detail below.

The steam manifold system 100 may include a steam manifold 140positioned about the end 110 of the transition piece 120 in the vicinityof the apertures 130. The steam manifold 140 may have any desired sizeor shape. The steam manifold 140 may include an internal cavity 150. Thecavity 150 may surround the end 110 of the transition piece 120. Thesteam manifold 140 may have a number of tubes 160 on one end thereon.The tubes 160 may be in communication with the apertures 130 of thetransition piece 120. Any number of the tubes 160 may be used. The tubes160 also may be positioned at an angle with respect to the stream of hotexhaust gases 125. As above, the angle may be about 30 to about 60degrees although any angle may be used. The tubes 160 may have anydesired size or shape as is described in more detail below. The steammanifold 140 also may have a number of purge holes 170 positionedtherein. Any number of the purge holes 170 may be used herein. The purgeholes 170 may have any desired size or shape.

The steam manifold system 100 may have a steam passage 180. The steampassage 180 may be in communication with the cavity 150 of the steammanifold 140. The steam passage 180 may have a valve 190 mountedthereon. The steam passage 180 may be mounted on an aft frame 200 of thetransition piece 120. Other positions may be used herein. The steampassage 180 may provide a volume of steam 210 to the cavity 150 of thesteam manifold 140. The quality and characteristics of the steam 210 mayvary.

In use, the steam 210 from the steam passage 180 may pass into thecavity 150 of the steam manifold 140. Most of the volume of the steam210 passes through the tubes 160 of the steam manifold 140, through theapertures 130 of the transition piece 120 and into the stream of hotexhaust gases 125 towards the turbine 40. A small volume of the steam210 may pass through the purge holes 170 and into a compressor dischargezone, mix with compressor airflow and then pass into combustor, thusreducing NO_(x) emission.

In a secondary mode of operation, the valve 190 of the steam passage 180may be closed. Air from the compressor discharge zone thus may passthrough the purge holes 170, the cavity 150 the tubes 160 of the steammanifold 140, and through the apertures 130 of the transition piece 120.

The steam manifold system 100 may be used on a MS6001V combustor offeredby General Electric Company of Schenectady, N.Y. The steam manifoldsystem 100 may be installed on any type of can, annular, or can-annulartype combustion system at the aft end of the transition piece 120 orotherwise.

Injection of the steam 210 just upstream of the turbine 40 thus providesfor enhanced power output and efficiency. The positioning of the steammanifold 140 about the end 110 of the transition piece 120 ensures thatthe steam 210 is injected downstream of the reaction zone of thecombustor 30 and just upstream of the turbine 40. The injection 40 ofthe steam 210 thus does not impact on the reaction temperature of thecombustor 30 such that CO emissions should not increase. The impact onflame stability also is lessened.

The steam manifold system 100 also may act as a type of a Helmholtzresonator. A Helmholtz resonator provides a cavity having a sidewallwith openings therethrough. The fluid inertia of the gasses within thepattern of the apertures 130 and the tubes 160 may be reacted by thevolumetric stiffness of the closed cavity 150 so as to produce aresonance in the velocity of the flow of the steam 210 therethrough. Thenumber, length, diameter, shape, position of the apertures 130, thetubes 160, and the volume of the cavity 150 may vary with respect to thedamping frequency range. Specifically, the design criteria may includethe size of the apertures 130 and the tubes 160, the diameter of theapertures 130 and the tubes 160, the number of the apertures 130 and thetubes 160, the mass flow rate through the cavity 150, and the volume ofthe cavity 150.

The dynamic pulsation spectrum of the combustor 30 may be determinedfrom known testing methods. The apertures 130 and the tubes 160 aresized to allow low velocity steam to discharge into combustor 30. Assuch, the dynamic pressure pulsations at any frequency may be dampenedby the steam manifold system 100. Further, the frequencies may bedampened without the use of a separate resonator. Any number of steammanifolds 140 may be used herein such that a number of differentfrequencies can be dampened.

The steam manifold system 100 thus provides power augmentation to thegas turbine engine 10 with minimal impact on increasing CO emissions orflame stability. Likewise, the steam manifold system 100 may effectivelydamp dynamic pulsations in the combustor 30 so as to improve operabilityand lessen durability risks. The steam manifold system 100 thusgenerally increases power output while also decreasing forced outagesand combustion inspection intervals. As such, the steam manifold system100 may reduce repair and operation costs.

It should be apparent that the foregoing relates only to certainembodiments of the present application and that numerous changes andmodifications may be made herein by one of ordinary skill in the artwithout departing from the general spirit and scope of the invention asdefined by the following claims and the equivalents thereof.

We claim:
 1. A power augmentation system with dynamics damping for a gasturbine engine, comprising: a transition piece of a combustor; a steammanifold positioned about the transition piece; the transition piececomprising a plurality of transition piece passageways therethrough; andthe steam manifold comprising a plurality of manifold passagewaystherethrough; the plurality of manifold passageways aligning with theplurality of transition piece passageways.
 2. The power augmentationsystem of claim 1, wherein the plurality of transition piece passagewayscomprises a plurality of apertures therethrough.
 3. The poweraugmentation system of claim 2, wherein the plurality of aperturescomprises a plurality of angled apertures.
 4. The power augmentationsystem of claim 1, wherein the steam manifold comprises a cavitytherein.
 5. The power augmentation system of claim 1, wherein theplurality of manifold passageways comprises a plurality of tubes.
 6. Thepower augmentation system of claim 5, wherein the plurality of tubescomprises a plurality of angled tubes.
 7. The power augmentation systemof claim 1, wherein the steam manifold comprises a plurality of purgeholes.
 8. The power augmentation system of claim 1, wherein thetransition piece comprises a frame and wherein the steam manifoldcomprises a steam passage positioned on the frame.
 9. The poweraugmentation system of claim 1, wherein the plurality of manifoldpassageways comprises a predetermined size based upon the frequency ofthe combustor.
 10. A power augmentation system with dynamics damping fora gas turbine engine, comprising: a transition piece of a combustor; asteam manifold positioned about the transition piece; the transitionpiece comprising a plurality of apertures extending therethrough; thesteam manifold comprising a plurality of tubes extending therethrough;the plurality of tubes comprising a predetermined size based upon thefrequency of the combustor; and the plurality of apertures aligning withthe plurality of tubes.
 11. The power augmentation system of claim 10,wherein the plurality of apertures comprises a plurality of angledapertures.
 12. The power augmentation system of claim 10, wherein thesteam manifold comprises a cavity therein.
 13. The power augmentationsystem of claim 10, wherein the plurality of tubes comprises a pluralityof angled tubes.
 14. The power augmentation system of claim 10, whereinthe steam manifold comprises a plurality of purge holes.
 15. The poweraugmentation system of claim 10, wherein the transition piece comprisesa frame and wherein the steam manifold comprises a steam passagepositioned on the frame.
 16. A power augmentation system with dynamicsdamping for a gas turbine engine, comprising: a combustor; a steammanifold positioned about the combustor; the combustor comprising aplurality of apertures extending therethrough; the steam manifoldcomprising a plurality of tubes extending therethrough; and theplurality of tubes comprising a predetermined size based upon thefrequency of the combustor.
 17. The power augmentation system of claim16, wherein the combustor comprises a transition piece and wherein thesteam manifold is positioned about the transition piece.
 18. The poweraugmentation system of claim 16, wherein the plurality of aperturesalign with the plurality of tubes.
 19. The power augmentation system ofclaim 16, wherein the plurality of apertures comprises a plurality ofangled apertures.
 20. The power augmentation system of claim 16, whereinthe plurality of tubes comprises a plurality of angled tubes.